Motorcycle Repair: VT1100c tranny noise, mileage engine, shadow vt1100c

Question
Hello..I am really hoping you can help...

About 3 years ago, the engine in my 87 Honda Shadow VT1100c was replaced witha low mileage engine from a 95 because 2nd gear had gone out...the new engine was supposed to have about 10k or less on it...that was at 52k or so on the bike...it has run great since then, until now.

Now, at 80k on the bike (about 40k on the engine) I am getting grinding noises in my tranny in 1st and 2nd gear...the bike is in gear just fine and all, but I get a grinding noise...sounds like something isn't where it is supposed to be inside or something isn't meshing right.  It seems to happen the most when slowing down after using the engine to decelerate or when revving...also had some noise in 2nd when climbing a long hill...also, once or twice I thought the bike jumped out of second, but it could have been my sloppy shifting...

It seems to take several miles to show up...I commute everyday to work, about 13 miles each way, and it usually doesnt start making the noise until I am about 8 or 10 miles into the commute.

A friend suggested it could be a bad clutch or basket or a bad U joint...but the noise really sounds like gears grinding...even though the bike seems to be firmly in gear, this noise occurs...and I can feel it in my left floorboard...

Can you offer any advise or insight?  Am I risking catastrophic failure of the engine by riding the bike?

Thanks in advance.

Answer
Hi Dave,

Q: "...Can you offer any advise or insight?

A: A tech will need to experience the problem to learn more about the cause. It's too difficult to accurately diagnose the problem without being present.


Q: Am I risking catastrophic failure of the engine by riding the bike?

A: Transmission failure may result with the rear wheel locking at speed. Attempts to steer while rear wheel sliding results with MC falling over.

I recommend having a tech inspect the problem via test ride.

Respectfully,
Mark Shively



Gear Shifting Faulty:

Doesn't go into gear; shift pedal doesn't return

Clutch not disengaging
Shift fork bent or seized
Gear stuck on the shaft
Gear position lever binding
Shift return spring weak or broken
Shift return spring pin loose
Shift mechanism arm spring broken
Shift mechanism arm broken
Shift pawl broken

Jumps out of gear:

Shift fork worn
Gear groove worn
Gear dogs and/or dog holes worn
Shift drum groove worn
Gear positioning lever spring weak or broken
Shift fork pin worn
Drive shaft, output shaft, and/or gear splines worn

Overshifts:

Gear positioning lever spring weak or broken
Shift mechanism arm spring broken